The concept of extending the "pot life" of pot contained coffee by introducing freshly brewed coffee into a substantially sealed coffee pot by way of a liquid trap and subsequently decanting coffee from the coffee pot through the same liquid trap whereby oxidation and evaporation of the pot contained coffee is substantially eliminated was introduced by applicant's parent application Ser. No. 532,980 which became abandoned subsequent to the filing of a copending, continuation application Ser. No. 921,881.
The present application is directed to improvements in that type top assembly, or "insert", illustrated in FIGS. 1-4 of parent application Ser. No. 896,712 used with conventional food service bowls of the type manufactured by Bloomfield Industries, Inc., 4546 W. 47th Street, Chicago, IL 60632.
Prior "inserts", or top assemblies, of the type with which the present invention is concerned have interfitted with the open top of a coffee pot via a deformable gasket, as in copending patent application Ser. No. 921,881, or integrally molded, deformable legs as in parent application Ser. No. 896,712. Extended usage of each of the foregoing methods of "sealing" an insert with respect to its associated coffee pot reveals that both are adversely affected by factors, inherent to their environment and usage, that cannot be controlled in production within realistic, commercial cost parameters. These factors are:
1) The inherent, production diameter variations in both the coffee pot opening and the insert; and
2) The relatively high temperature to which both the insert and its sealing means are exposed in usage.
In the case of the gasket sealed inserts, the peripheral portion of the "insert", or top assembly, on which the gasket is seated is intentionally formed with a lesser diameter than that of the coffee pot opening creating an annulus therebetween. The dimensions and flexibility of the gasket are, of course, chosen to accommodate any variation in annulus dimensions deriving from maximum .+-.tolerance variations in both the pot and insert to be expected in production. Since the thickness and flexibility of the gasket must be such as to accommodate the largest annulus (minimum insert/maximum pot opening tolerance) to prevent leakage when coffee is dispensed, the opposite set of tolerances (maximum insert/minimum pot opening) necessitates a "squeezing" of the gasket to seal within the thinner annulus. This produces two negative effects:
1) A significant manual effort to seat and remove the top assembly, the latter sometimes being accompanied by coffee spillage from the liquid trap as the top assembly first resists removal and then suddenly pulls free as the manual effort is increased; and
2) The "squeezed" gasket, under the influence of high temperature (upwards of 212.degree. F.) and radial compression, tends to take a "set" corresponding to the smaller annulus dimension whereupon subsequent use of the "squeezed" gasket with a different pot and insert defining a larger annulus results in leakage of the coffee during pouring.
In an insert designed specifically for a food service bowl characterized by a relatively small pour opening and upstanding, flaring pour lip it was thought to be feasible to form an insert having a geometrically similar pour lip, to overlap the bowl lip, and a peripheral portion thereof sized to interfit, itself, with the pour opening thus eliminating the gasket. The theory being that the lesser tolerance variation (due to the smaller interfitting components) would only vary between a "snug" and "tight" fit between the peripheral portion of the insert and the bowl opening. This arrangement is shown in parent application Ser. No. 896,712 wherein deformable legs, integral with the insert, provide a seating bias. Long term usage showed that this arrangement, too, is adversely affected by the high temperature environment. Thus when an over tolerance insert is "tightly" interfitted with an under tolerance bowl opening the peripheral portion of the insert takes a set conforming to the bowl opening whereupon subsequent usage of the same insert with a bowl having an over tolerance opening results in less than a snug fit. Similarly, the integral biasing legs take a set corresponding to a smaller bowl opening and fail to provide a good seating bias, when used with a larger mouth bowl, to maintain the overlapped pour lips fully seated.
A further improvement herein disclosed concerns an accelerated coffee pour rate and simplified mold tooling as compared with previous food service bowl inserts such as disclosed in parent application Ser. No. 896,712. In commercial food establishments where food service bowls of the type herein disclosed are employed in a high volume use environment; it is important from the standpoint of employee acceptance that the coffee pour rate, through a liquid trap, not be significantly less than the normal pour rate without a liquid trap. The manner in which a simple reorientation of parts comprising the liquid trap of the present invention results in both simplified mold tooling and an increased flow rate may be seen by comparison with the parent application drawings. Essentially, the liquid trap in both cases consists of three tubular portions forming a part of a coffee pot top assembly; an inner tubular portion open at both the upper and lower ends, surrounded by a larger intermediate tubular portion having a closed upper end and an open lower end which, itself, is surrounded by a larger outer tubular portion whose lower end, external of the intermediate tubular portion, is closed while its upper end is open. The open, lower end of the intermediate tubular portion is supported above the closed lower end of the outer tubular portion but below the open, upper end of the inner tubular portion to define the liquid trap. As freshly brewed coffee flows onto the top assembly from a coffee maker the space between the inner and outer tubular portions fills to submerge the open lower end of the intermediate tubular portion, creating a liquid trap between atmosphere and the interior of the coffee pot, and thereafter overflows the open, upper end of the inner tubular portion to drain through the open, lower end thereof into the coffee pot. When the pot is tilted to dispense coffee, the coffee flows from the pot through the open ended inner tubular portion and fills the closed end of the intermediate tubular portion (the normally upper end of the tubular portion being reversed, of course, when the pot is tilted to pour) and then overflows the open end thereof to enter the outer tubular portion from which it flows to a coffee cup or the like. That volume of coffee filling the closed end of the intermediate tubular portion while pouring functions, in effect, as a reservoir to refill the liquid trap once the coffee pot has again been righted, after pouring. In other words, the volume of coffee that is trapped in the closed end of the intermediate tubular portion is sufficient, when the pot is righted, to resubmerge the open end thereof so that the liquid trap is maintained after each cup of coffee is dispensed.
Coffee pour rate is, primarily, a function of the vertical distance the open, lower (as considered when the coffee pot is upright) end of the intermediate tubular portion is spaced above the closed bottom of the outer tubular portion and the radial distance between the intermediate and outer tubular portions. Obviously, the greater these distances the greater must be the reservoir volume of the closed upper end of the intermediate tubular portion to insure subsequent submergence of the open end thereof after dispensing. It is desirable, inter alia, from the standpoint of aesthetics to keep the dimensions of the reservoir as small as possible consistent with reestablishment of the liquid trap. The insert disclosed in the parent application employed a concentric orientation of tubular parts. In order to decrease the volume required to reestablish a liquid trap, and thus keep the reservoir dimensions relatively small, a "barrier" was molded between the intermediate and outer tubular portions on the non-pouring side of the insert.
In the instant application, the tooling required to mold the barrier is eliminated since the function of the barrier is replaced by a reorientation of the tubular portions which, also, increases pour rate. This is achieved by an eccentric, rather than concentric, orientation of the inner and intermediate tubular portions relative to the outer tubular portion thus increasing volume flow capacity on the pour side of the top assembly.